The present invention is directed to a lithotripter or lithotripsy device comprising a focussing means for a shockwave pulse emitted along a central axis, said lithotripter having first and second ultrasound transmission and reception apparatuses, which are arranged adjacent a focussing means in a fixed, three-dimensional relationship to aid in positioning the calculi or stone to be disintegrated.
A lithotripter is disclosed in German publication No. 27 22 252. This publication discloses a device having a reflector in the form of a ellipsoid, which is provided as focussing means. Two ultrasound transducers are secured to the housing wall of the reflector. The ultrasound transducers are adjusted so that they intersect the second focal point of the ellipsoid at an angle of about 30.degree.. The calculus or stone is identified according to the A-image method. In the exemplary embodiment described in the German application, the patient is arranged in a water bath so that displacement of the lithotripter does not involve any problems when coupling the shockwaves to the patient.
The situation is different when the lithotripter is coupled to the patient via a membrane and what is referred to as a "dry coupling", such as disclosed in U.S. Pat. No. 4,674,505, whose disclosure is incorporated by reference thereto and which patent claims priority from German Patent Application No. 33 28 051. When utilizing a "dry coupling", care must be exercised to see that the coupling membrane lies against the patient optimally unmodified during the locating procedure. Moreover, no difficulties should occur at a lithotripter when locating calculi in a complicated position, as can occur to a particular degree given, for example, gall stones.
U.S. Pat. No. 4,669,483, whose disclosure is incorporated by reference and which claims priority from German Patent Application No. 34 27 001, discloses a locating and positioning apparatus which works with an ultrasound resonator guided by a cardanic suspension. A three-dimensional spatial locating can be carried out here only with considerable outlay for the apparatus.